The idea is straightforward, but how will this actually work in practice?

Almost certainly automated behaviour is under computer control, as will be the overriding. "Overrides" will simply be inputs to the computer program, which it will understand as preemptive instructions, affecting whatever it would otherwise be doing.

The software is voluntarily allowing the override - it's programmed to allow its programming to be affected by some control. This is quite different from what we're accustomed to as overrides - traditional "manual overrides".

Overrides integrated into software are not manual overrides, and should not be represented as such to end users.